Antimicrobial composition of 3-iodo-2-propynylbutyl carbamate and 1,3-butylene glycol as solvent

ABSTRACT

An antimicrobial composition of 3-iodo-2-propynylbutyl carbamate (IPBC) and 1,3-butylene glycol (BG) as solvent, in a defined weight ratio, preferably 9-11% IPBC and 89-91% BG, and personal care formulations including the composition in an amount of about 0.1-0.2% therein, at a pH of 4-9, is described.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to preservative compositions for inhibiting the growth of microorganisms and fungi in personal care and industrial applications, and, more particularly, to preservative compositions which are effective and safe, are formaldehyde-free and paraben-free, are temperature and pH stable, and have broad compatibility with raw materials present therein.

2. Description of the Prior Art

Preservative compositions having antibacterial properties suitable for use in personal care and industrial applications have been described in the literature, see U.S. Pat. Nos. 3,923,870; 4,844,891; 5,428,050; 5,496,842; 5,552,425; 5,631,273; 6,582,627; and Published Application No. 2003/0039580.

However, each personal care formulation requires a preservative system that meets its specific needs, particularly for effective and safe preservation as determined by challenge testing.

SUMMARY OF THE INVENTION

What is described herein is an antimicrobial composition consisting essentially of 3-iodo-2-propynylbutyl carbamate (IPBC) in 1,3-butylene glycol (BG) as solvent, preferably, by wt., 9-11% IPBC in 89-91% BG, and personal care formulations containing 0.1-0.2% by wt. of the preservative composition, at a pH of 4-9 of the composition.

The preservative compositions herein are effective and safe, are formaldehyde-free and paraben-free, are temperature and pH stable, and are compatible with raw materials present in both personal care and industrial products.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be illustrated in more detail by the following examples.

EXAMPLE 1

NON-IONIC MOISTURIZER SUP- PHASE INGREDIENT % W/W PLIER A Deionized Water 78.70 Disodium EDTA (Versene NA) 0.10 Dow Glycerin (and) Glyceryl Acrylate/ 0.50 ISP Acrylic Acid Copolymer (and) Butylene Glycol (and) PVM/MA Copolymer (LUBRAJEL ® OIL BG) Sodium Polyacrylate 0.75 ISP (RAPITHIX ® A-100) B Octyldodecyl Stearate 3.50 ISP (CERAPHYL ® ODS) Isostearyl Neopentanoate 3.50 ISP (CERAPHYL ® 375) Diisopropyl Adipate 2.50 ISP (CERAPHYL ® 230) Ethylhexyl Palmitate 2.50 ISP (CERAPHYL ® 368) C₁₂₋₁₅ Alkyl Lactate 3.00 ISP (CERAPHYL ® 41) Glyceryl Stearate (and) 1.25 ISP Laureth-23 (CERASYNT ® 945) Peg-20 Stearate (CERASYNT ® 840) 1.00 ISP C Cyclopentasiloxane 2.50 ISP (SI-TEC ™ CM 040) D 1,3-Butylene Glycol and 0.20 ISP Iodopropynyl Butylcarbamate (LIQUAGARD ™) 100.00%

Procedure

-   -   1. Combine Phase A except for Rapithix A-100. Sprinkle in         Rapithix A-100 with good mixing.     -   2. Combine Phase B with mixing and heat to 70° C.     -   3. When Phase A is uniform and Phase B is at 70° C. slowly add         Phase B to Phase A with good mixing.     -   4. When batch is uniform add Phase C with good mixing.     -   5. Add Phase D and mix until the batch is completely uniform.

Challenge Tests

The challenge test is a 28-day test used to verify the effectiveness of a preservative system in a personal care formulation. Selected personal care formulations were inoculated with microorganisms at the onset of testing (0 hours), then sampled at 48 hours, 7 days, 14 days, 21 days, and 28 days. At 21 days the formulations were re-inoculated with the same microorganisms. Pass/fail criteria were based on modified Cosmetic, Toiletry and Fragrance Association (CTFA) protocol.

The invention composition was tested in several systems and found to effectively preserve a variety of personal care formulations against the following microorganisms:

Microorganism Abbreviation Candida albicans CAN Aspergillus niger AN

Inoculum Concentration (CFU/g) Organism 0 Hours 21 Days CAN ATCC 10231 1.9 × 10⁶ 5.0 × 10⁵ AN ATCC 16404 3.0 × 10⁵ 1.0 × 10⁶

Preservative Efficacy Test Results (CFU/g) Organism 48 Hrs 7 Days 14 Days 21 Days 28 Days CAN ATCC >1.0 × 10⁶ <10 <10 1.0 × 10² <10 10231 AN ATCC <10 <10 <10 <10 <10 16404

Accordingly this formulation of Example 1 passed a 28-day double challenge efficacy test.

Based on this challenge test data, Liquagard™ is recommended for use in personal care products at levels between 0.1%-0.2% within a broad pH range of 4.0-9.0.

EXAMPLE 2

SHOWER GEL PHASE INGREDIENT % W/W SUPPLIER A Deionized Water 51.45 Disodium EDTA 0.10 Dow Chemical Polyquaternium-7 2.50 ISP (CONDITIONEZE ® 7) Glycerin 2.50 Benzophenone-4 0.20 ISP (ESCALOL ® 577) B Ammonium Lauryl Sulfate 30.00 Rhodia Cocamidopropyl Betaine 10.00 Goldschmidt Cocamide DEA 2.50 Cognis C PEG-7 Glyceryl Cocoate 0.30 Cognis Fragrance (#01779396) 0.10 Dragoco Blue #1 (.1% Aq. Solution) 0.20 Warner Jenkinson D 1,3-Butylene Glycol and 0.15 ISP Iodopropynyl Butylcarbamate (Liquagard ™) 100.00%

Procedure

-   -   1. Combine Phase A with mixing and begin heating to 65° C.     -   2. When Phase A is uniform add Phase B in the order listed with         mixing.     -   3. Start cooling the batch.     -   4. Add Phases C & D at 30° C. with mixing.     -   5. QS for water loss and mix to RT.         pH=7.6 Viscosity=7,200 cps (Brookfield Model RVT, TB @ 5 RPM)

Inoculum Concentration (CFU/g) Organism 0 Hours 21 Days CAN ATCC 10231 4.9 × 10⁶ 6.6 × 10⁶ AN ATCC 16404 1.0 × 10⁶ 2.4 × 10⁶

Preservative Efficacy Test Results (CFU/g) Organism 48 Hrs 7 Days 14 Days 21 Days 28 Days CAN ATCC <10 <10 <10 <10 <10 10231 AN ATCC <10 <10 <10 <10 <10 16404

The formulation of Example 2 passed the 28-day double challenge efficacy test.

EXAMPLE 3

-   PRODUCT: Shower Gel -   USE LEVEL: 0.02% Liquagard (200 ppm active IPBC)

REINOCULUM TEST ORGANISM INOCULUM (0 hours) (21 days) Candida albicans 10231 4.9 × 10⁶ cfu/g of product 6.6 × 10⁶ cfu/g Aspergillus niger 16404 1.0 × 10⁶ cfu/g of product 2.4 × 10⁶ cfu/g

Assay Interval Test Organism 48 Hrs 7 Days 14 Days 21 Days 28 Days Candida albicans <10 <10 <10 <10 <10 Aspergillus niger <10 <10 <10 <10 <10

EXAMPLE 4

SCREENING EMULSION PHASE INGREDIENT W/W % A Stearic acid 5.00 Mineral oil 2.50 Cetyl alcohol, NF 1.00 Ceteareth-5 0.50 Glyceryl Stearate and PEG-100 Stearate 1.50 B DI water 87.90 Triethanolamine (99%) 1.00 C 1,3-Butylene Glycol (and) Iodopropynyl 0.10 Butylcarbamate (LIQUAGARD ™) D Citric acid 30% aqueous 0.60

Procedure:

-   -   1. Heat Phase A to 75° C. Heat Phase B to 75° C.     -   2. Add Phase A to B under moderate sheer with overhead mixer.         Remove heat and continue mixing throughout preparation.     -   3. Add Phase C at the appropriate temperature (° C.).     -   4. Add Phase D at 35-40° C.     -   5. Cool to 30-35° C.     -   6. QS with water. Remove contents to a storage container         reserving enough in the beaker to measure a pH. Store in         refrigerator.

EXAMPLE 5 Antifungal Efficacy Data

-   Formulation: Screening Emulsion -   Liquagard: 10% IPBC in 1,3 butylene glycol -   Test Method: MLM 100-9

Inoculate formulation at 0 hours. Assay at 48 hours, 7 days, 14 days, 21 days. Re-inoculate at 21 days and then final assay at 28 days. Inoculum counts are listed in Table I. Two levels of Liquagard were tested; the data is contained in Tables II and III below.

TABLE I REINOCULUM TEST ORGANISM INOCULUM (0 hours) (21 days) Aspergillus niger 16404 2.0 × 10⁵ cfu/g 3.8 × 10⁵ cfu/g Taloromyces luteus 3.9 × 104 cfu/g 4.0 × 106 cfu/g Candida albicans 10231 2.0 × 10⁶ cfu/g 1.5 × 10⁶ cfu/g

TABLE II 0.05% Liquagard (50 ppm IPBC) Test Organism 48 Hrs 7 Days 14 Days 21 Days 28 Days A. niger <10 <10 <10 <10 <10 T. luteus <10 <10 <10 <10 <10 C. albicans <10 <10 <10 <10 <10

TABLE III 0.1% Liquagard (100 ppm IPBC) Test Organism 48 Hrs 7 Days 14 Days 21 Days 28 Days A. niger <10 <10 <10 <10 <10 T. luteus <10 <10 <10 <10 <10 C. albicans <10 <10 <10 <10 <10

EXAMPLE 6 Liquagard vs Controls

-   PRODUCT: Screening emulsion -   USE LEVEL: 100 ppm active IPBC

REINOCULUM TEST ORGANISM INOCULUM (0 hours) (21 days) Candida albicans 10231 7.2 × 10⁶ cfu/g of product 3.0 × 10⁶ cfu/g Aspergillus niger 16404 1.5 × 10⁶ cfu/g of product 7.0 × 10⁶ cfu/g

Assay Interval Test Organism 48 Hrs 7 Days 14 Days 21 Days 28 Days Liquagard ™ Candida albicans <10 <10 <10 <10 <10 Aspergillus niger <10 <10 <10 <10 <10 Glycacil L* (Lonza) Candida albicans <10 <10 <10 <10 <10 Aspergillus niger <10 <10 <10 <10 <10 Unpreserved Candida albicans >1E6 >1E6 >1E6 Aspergillus niger >1E6 >1E6 >1E6 *Glycacil L - polyethylene glycol monococoate (~40%), polyethylene glycol dicocoate (~40%), 3-iodo-2-propynyl butyl carbamate (~10%) and polyethylene glycol (~10%).

EXAMPLE 7

NON-IONIC EMULSION PHASE INGREDIENT % W/W SUPPLIER A Deionized Water 70.10 PVM/MA Decadiene 0.20 ISP Crosspolymer (Stabileze ® QM) B Ethylhexyl Palmitate 10.00 ISP (Ceraphyl ® 368) Cetearyl Alcohol and 2.00 Amerchol Ceteareth-20 (Promulgen D) Glyceryl Stearate and 2.50 ISP Laureth 23 (Cerasynt ® 945) Isocetyl Stearate 10.00 ISP (Ceraphyl ® 494) C Triethanolamine (99%) 0.20 Deionized Water qs 1,3-Butylene Glycol and 0.20 ISP Iodopropynyl Butylcarbamate (Liquagard ™) 100.00%

Procedure:

-   -   1. Sprinkle Stabileze into water with stirring at RT. Heat phase         A to 75° C.     -   2. Combine Phase B, heat to 85° C.     -   3. Combine Phase B to A with stirring, at 75° C.     -   4. When batch is uniform add Phase C.     -   5. When uniform turn off heat.     -   6. Continue stirring thru cool down.     -   7. Make up water loss and stir at RT. Store in refrigerator.

EXAMPLE 8 Liquagard vs Controls

-   PRODUCT: Nonionic Emulsion -   USE LEVEL: 200 ppm active IPBC

REINOCULUM TEST ORGANISM INOCULUM (0 hours) (21 days) Candida albicans 10231 7.2 × 10⁶ cfu/g of product 3.0 × 10⁶ cfu/g Aspergillus niger 16404 1.5 × 10⁶ cfu/g of product 7.0 × 10⁵ cfu/g

Assay Interval Test Organism 48 Hrs 7 Days 14 Days 21 Days 28 Days Liquagard ™ Candida albicans 3.1 × 10⁴ <10 <10 <10 <10 Aspergillus niger 5.0 × 10⁴ <10 <10 <10 <10 Control - Glycacil L Candida albicans 8.5 × 10⁵ <10 <10 <10 3.0 × 10¹ Aspergillus niger 1.9 × 10⁵ <10 <10 <10 <10 Unpreserved Candida albicans >1.E6 >1E6 >1E6 Aspergillus niger  >1E6 >1E6 >1E6

In summary, the invention Liquagard™ (ISP) composition can be effectively used in personal care compositions including:

Skin Care Compositions

Sunscreen creams and lotions; moisturizers; night creams; hand/body creams and lotions; shaving products; cleansing products; wipes; foundations; concealers; body washes; shower gels; liquid hand soaps and baby products.

Hair Care Compositions

Shampoos, conditioners; deep conditioning treatments; styling gels, mousses, shine lotions, hair colorants and baby products.

While the invention has been described with particular reference to certain embodiments thereof, it will be understood that changes and modifications may be made which are within the skill of the art. Accordingly, it is intended to be bound only by the following claims, in which: 

1. An antimicrobial composition consisting essentially of 3-iodo-2-propynylbutyl carbamate (IPBC) in 1,3-butylene glycol as solvent.
 2. An antimicrobial composition according to claim 1 consisting essentially of, by wt., 9-11% IPBC and 89-91% 1,3-butylene glycol.
 3. A personal care formulation including the antimicrobial composition of claim
 1. 4. A personal care formulation containing 0.1-0.2% by wt. of the composition of claim
 2. 5. A personal care formulation according to claim 4 at a pH of 4-9.
 6. A personal care formulation according to claim 3 which is a skin care product.
 7. A personal care formulation according to claim 3 which is a hair care product.
 8. A personal care formulation according to claim 6 which is a non-ionic moisturizer.
 9. A personal care formulation according to claim 3 which is a shower gel.
 10. A personal care formulation according to claim 3 which is a screening emulsion.
 11. A personal care formulation according to claim 3 which is a non-ionic emulsion.
 12. An industrial product which includes the antimicrobial composition of claim
 1. 